Process of making sulfite liquor.



A. F. RICHTER & T. L. DUNBAR.

PROCESS OF MAKING-SULFITE LIQUOR.

APPLICATION FILED OCT. 9, 19M.

Patented Jan. 23, 1917.

Witnesses UNITED STATES PATENT OFFICE.

AUGUST E. RICHTER AND THOMAS L. DUNBAR, or WATERTOWN, NEW YoRK.

Specification of Letters Patent.

Patented Jan. 23. 1917.

Application filed October 9, 1914. Serial No. 865,921.

T 0 all whom it may concern Be it known that we, AUcUs'r F. RICHTER and THOMAS L. DUNBAR, citizens of the United States, residing at \Vatertown, in the county of Jefferson, State of New York, have invented a new and useful Process of Making Sulfite Liquor, of which the following is a specification.

In the sulfite paper pulp process, the practice heretofore'has been to deliver the sulfur dioxid gas and spent liquor, received from the digesters during the cooking operation, into the storage tanks. Many previous attempts have been made to carry the liquor back to the S0 absorption acid-making apparatus and either to mix the liquor with the lime-water or to admit the liquor directly into the S0 absorption system. This method, however, has failed, due to difliculties produced by foaming.

The present process deviates from former ones as applied to the calcium bisulfite making process, in the distinct feature embodied in mixing the spent liquor from the digesters, after the liquor has been cooled, with a halfmade sulfite liquor. The said liquor, carrying an abundance of unconsumed lime, readily combines with the spent liquor from the digesters, and this operation takes place without foaming or other undesirable results. The liquor thu's-produced is enriched and strengthened markedly by the absorption of sulfur dioxid gas derived from the sulfur burners, the liquor being delivered, in a separate tank and in the form of a spray or mist, into the sulfur dioxid derived from the burners, and in a direction opposed to the flow of gas in the tank.

In order to secure a perfect mixture of the sulfite liquor and the spent liquor from the digesters, these fluids are brought together in a pipe-union or fitting prior to, entering the absorption tank, the union or fitting acting as an injector and promoting the mingling of the sulfite liquor and the liquor from the digesters.

To aid in accomplishing the most thorough absorption of the sulfur dioxid gas from the...

burners by the liquor in the-absorption tank, the-latter is provided with'aaserie s of bafiies and the liquid formed by the union of the spent liquor and the sulfite liquor is sprayed between the bafiles, thus causing a long and continuous contact between the gas and the liquid. The sulfur dioxid gas which is not absorbed in the tank is returned and combined with calcium bisulfite to produce the sulfite liquor required to keep the apparatus in uniform and continuous operation. From the separator, which receives the gas and liquor from the digester, the salvaged gas is" conveyed to an absorption tower and then is mingled with the liquid derived from the ab- I sorption tank, the product passing to a suitable storage vessel.

In the accompanying drawing, there is shown diagrammatically, one form of apthe products from a digester are conveyed to the separator 1. A

The numeral 3 indicates a sulfur-dioxid absorption tower Provided in its interior with baffles 1. The sulfur-dioxid from the separator 1 is conveyed to the bottom of the absorption tower 3 through a pipe 5, the spent liquor from the separator l passing therefrom through a pipe 6. The pipe 6 communicates with a manifold 7 having a plurality of arms 8 provided upon their lower faces with perforations 9. The arms 8 enter an absorption tank 10 provided with oppositely extended bafiies 11, the arms 8 lying between the baflies. In their lower edges, the baffles 11 are provided with small openings 12 permitting the liquid in the ab sorption tank to pass through the baffles.

A pipe 14 leads from sulfur burners (not shown) througlrone end of the absorption tank 10. From the top of the absorption tank 10 a pipe 20 passes to a tank 16, there being a tank 15 provided with a pipe 19 which leads to the exhauster (not shown).

-The tanks 15 and 16 are connected by pipes 17 and 18. Leading from the tank 16 is a pipe 21 entering a union 22 interposed in the pipe 6. In the pipe 21 is placed a pump 23. Apipe 24 leads from the bottom of the absorption tank 10 to the top of the sulfur dioxid absorption tower 3 and in the pipe 24 is interposed a pump 25; From the tower 3, near the bottom thereof a pipe 26 leads to storage tanks 27.

The products roceeding from the digester (not shown enter the separator 1 by way of the pipe 2. From the separator 1,

' abundance of unconsumed lime and combines readily with the spent liquor without foaming and without producing other undesirable results. The union 22 acts to some extent as an injector, and serves to effect a thorough mingling of the sulfite liquor and the spent liquor in the digester. The liquid thus produced passes into the manifold? and by way of the arms 8 into the tank 10. Here, the li uid is delivered downwardly in a s ra or 0am, between the baffles 11 and is isc arged downwardly in a direction opposite to that taken by the sulfur dioxid gas introduced into the absorption tank 10 from the burner pipe 14 during the upward travel of the gas between the bafiies 11. The excess sulfur dioxid in the tank 10 passes by way of the pipe 20 into the tanks 16-15 and here is mingled with calcium bisulfite to roduoe the sulfite liquor which, in its turn, is delivered to the pipe 6 by way of the pipe 21. The liquid in the tank 10 passes by way of the ipe 24 into the tower 3 and here is minglezfwith the sulfur dioxid from separator 1, the pipe 5 serving to convey the sulfur dioxid from the separator to the tower. From the tower 3, the li uid passes by way of the pipe 26 into the tan s 27.

Having thus described the invention, what is claimed as new is A process of making sulfite liquor, which sulfite liquor and the sulfur dioxid fromth'e burner.

In testlmony that We claim the foregomg as our own, we have hereto aflixed our signatures in the presence of two. Witnesses.

AUGUST F. RICHTER. THOS. L. DUNBAR.

Witnesses for Richter: GEO. A. STEBBINS, F. E. KENNEDY.

\Vitnesses for Thos. L. Dunbar:

WILLIS I. FLETCHER, GEORGE HARRIS.

Copies of this patent may be obtained for five cents each, ty addressing the Commissioner of Patents, Washington, D. G. 

